The age of a patient is a strong moderator of both the course and the evolution of disorders/diseases. However, the effects of current age in pathological gambling (PG) have rarely been examined. The aim of this study is to explore the moderating effects of the patients’ current age in relation to personality traits and clinical outcomes of PG. A total sample of 2,309 treatment-seeking patients for PG, diagnosed according to DSM-IV criteria, participated in this study and were assessed with the Diagnostic Questionnaire for Pathological Gambling according to DSM-IV criteria, the South Oaks Gambling Screen, the Symptom Checklist, the Temperament and Character Inventory-R, and other clinical and psychopathological measures. Orthogonal polynomial contrasts showed linear trends in the relationship between age and PG: the older the patient, the more comorbid health problems were visible. The presence of additional quadratic trends also suggests that age plays a significant role in moderating the possibility of existing PG problems and general psychopathology. No interaction term was found between age and sex, but it was present for age and some personality traits: self-transcendence and reward dependence (these two traits were only relevant to the level of impairment due to PG at specific ages). This study suggests that the patients’ age influences psychopathological and clinical aspects associated to PG. Intervention in the earliest manifestations of this complex problem is essential in order to better address the need of successful treatment planning.